SXR SXR-1500 Impeller Thread Size?

[CARBONX2]

I have a Freedom Racing set-back pump, and fitting it to my WB3 running a STXR-1200 engine/pump. I need the shaft for inside the pump
The impeller they gave me has a 18mm thread, which is larger than any Kawi pump I have to compare with
Is the SXR-1500 an 18mm thread? Want to be sure before I order.

 

[WB800BLASTER]

please send pics of WB3 when completed.

Thanks
Pat

 

[CARBONX2]

Been running for a while, parked for the last year after race organisers more interested in their own pocket than pilot safety. 64mph on track with stock pump and stock porting. Will find pics